A nurse is administering methotrexate, an antimetabolite, to a client who has osteosarcoma. The nurse should identify that methotrexate can cause which of the following adverse effects? (Select all that apply.)

Choice A reason: Blocking the estrogen receptors on the cancer cells and inhibiting their growth is the mechanism of action of tamoxifen, a selective estrogen receptor modulator (SERM) that is used to treat breast cancer. Tamoxifen is not effective for prostate cancer, which is stimulated by testosterone, not estrogen.

Choice B reason: Stimulating the production of testosterone and increasing the sensitivity of the cancer cells to chemotherapy is not the mechanism of action of leuprolide, a hormone that is used to treat prostate cancer. Leuprolide does not increase testosterone, but decreases it. Increasing testosterone would worsen prostate cancer, not improve it.

Choice C reason: Suppressing the secretion of luteinizing hormone and reducing the level of testosterone is the mechanism of action of leuprolide, a gonadotropinreleasing hormone (GnRH) agonist that is used to treat prostate cancer. Leuprolide binds to the GnRH receptors in the pituitary gland and initially stimulates the release of luteinizing hormone (LH) and folliclestimulating hormone (FSH). However, with continuous administration, leuprolide desensitizes the receptors and inhibits the secretion of LH and FSH. This leads to a decrease in the production of testosterone by the testes, which reduces the growth of prostate cancer cells.

Choice D reason: Altering the metabolism of cortisol and inducing apoptosis of the cancer cells is not the mechanism of action of leuprolide, a hormone that is used to treat prostate cancer. Leuprolide does not affect cortisol, but testosterone. Cortisol is a glucocorticoid hormone that regulates stress response, inflammation, and metabolism. Apoptosis is a process of programmed cell death that can be triggered by some chemotherapy drugs, such as cisplatin and doxorubicin.

Choice A reason: Methotrexate is an antimetabolite that inhibits the synthesis of DNA and RNA, which are essential for cell division and growth. Methotrexate affects rapidly dividing cells, such as those in the bone marrow, where blood cells are produced. This can lead to bone marrow suppression, which is the reduction of the number and function of blood cells, causing anemia, leukopenia, thrombocytopenia, or pancytopenia. The nurse should monitor the client's complete blood count, signs of infection, bleeding, or fatigue, and administer leucovorin (a rescue agent) to prevent or treat this complication .

Choice B reason: Ototoxicity is not a common adverse effect of methotrexate. Ototoxicity is the damage to the inner ear or auditory nerve caused by certain drugs, such as aminoglycosides (e.g., gentamicin) or loop diuretics (e.g., furosemide). Ototoxicity can cause hearing loss, tinnitus, vertigo, or balance problems .

Choice C reason: Gastrointestinal toxicity is a common adverse effect of methotrexate. Gastrointestinal toxicity is the irritation of the mucous membranes of the digestive tract, causing nausea, vomiting, diarrhea, or mucositis. Methotrexate can also cause hepatotoxicity, which is the damage to the liver cells. The nurse should monitor the client's liver function tests, weight, fluid intake and output, and nutritional status. The nurse should also provide antiemetics, mouth care, hydration, and small frequent meals to prevent or manage this complication .

Choice D reason: Neurotoxicity is not a common adverse effect of methotrexate. Neurotoxicity is the damage to the brain or nervous system caused by certain drugs, such as platinum compounds (e.g., cisplatin) or vinca alkaloids (e.g., vincristine). Neurotoxicity can cause confusion, seizures, peripheral neuropathy, or encephalopathy .

Choice E reason: Skin reactions are a common adverse effect of methotrexate. Skin reactions include rash, pruritus, photosensitivity, alopecia, or erythema multiforme. The nurse should inspect the client's skin regularly, provide skin care, avoid exposure to sunlight or ultraviolet light, and apply sunscreen and moisturizer to prevent or treat this complication .